import React from "react";
import {BrowserRouter as Router,Route,Link} from "react-router-dom";

//Home组件
const Home = () => (
    <div>
        <h2>Home</h2>
    </div>
)

//About组件
const About = () => (
    <div>
        <h2>About</h2>
    </div>
)

//Topic组件
const Topic = ({match}) => (
    <div>
        <h3>{match.params.topicId}</h3>
    </div>
)

//Topics组件
const Topics = ({match}) => (
    <div>
        <h2>Topics</h2>
        <ul>
            <li><Link to={`${match.url}/rendering`}>Rendering with React</Link></li>
            <li><Link to={`${match.url}/components`}>Components</Link></li>
            <li><Link to={`${match.url}/props-v-state`}>props-v-state</Link></li>
        </ul>
        <Route path={`${match.path}/:topicId`} component={Topic}/>
        <Route exact path={match.path} render={()=>(
            <h3>please select a topic!!!</h3>
        )}></Route>
    </div>
)

const AppHome = () => (
    <Router>
        <div>
            <ul>
                <li><Link to="/">Home</Link></li>
                <li><Link to="/about">About</Link></li>
                <li><Link to="/topics">Topics</Link></li>
            </ul>

            <hr/>

            <Route exact path="/" component={Home}/>
            <Route path="/about" component={About}/>
            <Route path="/topics" component={Topics}/>
        </div>
    </Router>
)

export default AppHome

